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Questions tagged [electrical]

128 questions
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Does good electrical conductivity imply good thermal conductivity?

Typically materials which are good conductor of electricity are also good conductor of heat, and vice versa. Are there notable exceptions?
zxc
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11
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Extending USB cable makes it not work

I have a camera that uses a USB cable to connect to my computer. I want to extend the cable from 3ft to about 6ft. Originally I just created my own cable, soldering 4 26AWG wires to a blank USB connector and connecting the other side to the correct…
Jack Campbell
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How do electric companies supply electricity to homes in countries where energy is privatized?

Before I start, sorry if this doesn't make sense English is not my first language. In my country electricity is nationalized so there is only one energy company and one grid. When you build new house you just connect your house cables to the…
gbd
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Why do electric cars claim "instant torque?"

I was at a well-known electric car company today and they claimed "instant torque." The quote was something like the following: Driving this car is very different from a gas-powered vehicle. For example, it has instant torque when you press the…
Mowzer
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4
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2 answers

How do electric vehicles' motors run at high speeds above 10000rpm?

For example, for a squirrel cage induction motor, the speed of operation is given by Ns = 120*f/P depending on the number of pole pairs and supply frequency. Now the supply frequency is 50/60Hz while the minimum number of pole pairs is 2. This…
Santhosh Srinivasan
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4
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1 answer

Quantifying Static Electricity Hazard with High Explosives

In the making of firework explosives, the explosive mixtures are handled with great care to avoid static electricity induced detonation of the explosives. Is it a good idea that they store the explosives in a plastic container - isn't there a risk…
Hypnos Stratagem
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Electrostatic grounding of an electrically isolated concrete floor

I have a question regarding a not-so-common construction setup for a house. In this situation, the concrete slab is "floating"/insulated with a rigid insulation underneath. I understand the slab is not grounded and there's a risk for static charge…
lpezet
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3
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Does electricity go through non-metal materials or not?

Ever since I was a little boy, I've always had this idea that electricity can only go through metal materials. For example, if I put a 100% metal screwdriver into the socket in the wall, I'm going to get electrocuted. Logical. Or if I take a long…
user33010
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2 answers

AC Motor On/OFF Control using SSR instead of contactor

I would like to control a 1-phase 3HP motor using a SSR ( the reason being, I need to switch it on/off using a signal (0-5VDC). Are normal SSRs (ex:Fotek 40A model) capable of handling the starting current of a 3HP motor? What are the protection…
ZenMaster
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What is the material requirement for Van der Graff generator sphere?

I would like to make a Van der Graff generator for my science fair project out of aluminized mylar. Do you think this might be feasable or do I need to use thick stainless steel ball? Is there some sort of charge or conductivity limit that I need to…
user2820052
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Balancing Locomotive Power

My first post here. I'm curious about how power is balanced in multiple diesel-electric locomotives. I understand to that two locos can be ganged in terms of controls, to set speed etc, so that one set of driver controls manages the whole pulling…
Steve Taylor
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Why did the metal railings to the stairs in the big ferries used to shock me?

When I was a kid, and even in adult age, I sometimes went on these large (well, to me, at least) cruise ships which had multiple (like ten) levels to roam around in. You either got there with the elevators or with the stairs. Whenever I picked the…
Venton Selland
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Eliminate cat ear and nose shocks during the dry season

My cat, George Valentine, really enjoys being pet. However, when the air here in Canada gets very dry (mid-fall), this activity creates static charges. Once the petting starts giving him relentless shocks to his tender ears and nose, he gets quite…
James Orr
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2
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4 answers

Inverting motor polarities automatically to close and open a door

Hi, I need to build a device that opens a chicken coop door. The idea is quite simple, a motor connected to an axle that pulls a string up just like a wench. It would be activated by a relay timer setting it to open at 2 different times of the day…
Renan
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2
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Transferring the project from "Altium Design" to "SolidWorks" while maintaining silk-screen printing, sizes and everything else

I want to transfer the PCB project to solidwork from altium design, I read forums on how to do it better, and so: Save to STEP. The option is good and working, but I did not like the option, since silk-screen printing and tracks on the PCB are not…
Антон
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